• Inserts identifiers into the symbol table.
• Records token attributes like identifier names.

• Updates attribute information such as scope and structure.
• Maintains hierarchical scope information.

• Performs type checking.
• Verifies declarations before use.
• Validates function parameters and return types.

• Uses type and size information.
• Adds temporary variables into the symbol table.

• Uses scope and type information.
• Assists in memory and register optimization.

• Uses memory location and offset information.
• Generates correct machine instructions.

Let us consider the following program

# include <stdio.h>
 
const float pi = 3.14159f;

float calculateArea(float radius, float pi) {
    return pi * radius * radius;
}

int main() {
    float distance;             
    
    printf("Enter the distance (radius): ");
    if (scanf("%f", &distance) != 1) {
        printf("Invalid input!\n");
        return 1;
    }
    
    float area = calculateArea(distance, pi);
    printf("Area of circle with radius %.2f = %.5f\n", distance, area);
    
    return 0;
}

Key identifiers involved:

• distance (variable in main)
• pi (constant)
• radius (parameter in calculateArea)
• calculateArea (function)

main

calculateArea

A symbol table of this program would look like the following.